Drug driving law will hit medicine users

Motorists using prescribed painkillers such as morphine and codeine could be charged with "drug driving" under a new law designed to keep dangerous hard drug users off British roads, doctors and campaigners have warned.

Ministers have confirmed that the "opioid-based medicines" may be covered by the new offence of drug-driving, even if they have been supplied by a doctor and the recommended dose is taken. At present, motorists and their doctors must be satisfied of their fitness to drive before they get into a car.

The Government is introducing the new law amid growing concerns about drug-users behind the wheel. It will make it easier for police to take action by making it an offence for motorists to drive with controlled drugs in their body.

Ministers have insisted they are targeting the worst threats, particularly those who go on the road after using Class-A drugs such as heroin and cocaine. However, critics have complained that the measures could hit innocent motorists who take legitimate painkillers to ease often chronic conditions.

The British Medical Association warned that "blanket bans" on motorists driving after taking medication could "meet considerable legal challenge unless there is clear evidence that links exposure to known levels of driving impairment, as is the case with alcohol".

Baroness Hamwee, a Liberal Democrat peer, complained that the proposals could punish motorists who took their prescribed medicines at the doses recommended by their doctor: "If the [drug-ban] level is set at zero, this will disqualify, for instance, thousands of people taking very common medicines that control, to take just one example, raised blood pressure.

"Patients with chronic pain who are on a stable dose of a prescription or over-the-counter opioid analgesic may well be over the limit without impairment, while some may be impaired and some not because there is a variable impact."

Dr Beverly Collett, chair of the Chronic Pain Policy Coalition, welcomed the move to criminalise driving while intoxicated by recreational drugs. But she added: "Opioids and other medications are taken by people living with pain, and pain itself can cause cognitive impairment."

The Transport Research Laboratory has estimated that drugs are a key factor in nearly a quarter of fatal road accidents. A 2009 study funded by the Government found that one in 10 young motorists admitted to driving after taking illegal drugs.

However, the number of motorists breathalysed for drink-driving dwarfs the total tested for narcotics, prompting ministers to sanction the distribution of new drug-screening devices to UK police forces.

Department for Transport officials insisted the existing legislation on driving while impaired by drugs covered both illegal and prescribed substances. Mike Penning, the transport minister, said the new offence allowed motorists a statutory defence where they had taken medicines "containing specified controlled drugs in accordance with medical advice" – although they could have to go before a court to plead.

Mr Penning added: "Drug drivers are a deadly menace – they must be stopped, and that is exactly what I intend to do. The new offence sends out a clear message that if you drive while under the influence of drugs, you will not get away with it."